Self-setting tubular rivet



Oct; 1, 1946. J K I 2,408,559 SELFLSETTING T BULAR RIVET Filed June 19,1945 Fig.2. Pig. 2.

INVEN TOR.

HERBERT JK ATING,

Patented Oct. 1, 1946 UNITED STATES PATENT oF -E 2,408,559 SELF-SETTINGTUBULAR RIVET 1 Herbert J. Keating, Pasadena, Calif assignor to CherryRivet Company, LosiAng'eles, Califi, a corporation of California I eachother .is accomplished by protrude videdwith external threads toengagethreads on "The rivet opening in the inner work. sheet, theremainder of the shank of the rivet being cylin- A pplication June 19,1945, Serial No. 600,332

2 Claims. (01 85 -40) My invention relates .to tubular rivets and hasparticular reference to a self-setting tubular rivet of the blind rivettype adapted to be inserted in aligned holes in a pair ofv workpieces tobe secured tubular rivet of the character described wherein thesecuringof the workpieces intight relation to employing a rivet having a shank,a portion of Which'js adapted to through the inner work sheet and ispro- .d'rical and smooth whereby a rotational movementimpartedto therivet will cause the head of the rivet to be drawn into contact withtheouter work sheet and then continuedrotary movement will cause all of theworksheets to be tightly clamped together prior .to the upsetting of thetogether by said rivet and in which a rotary moveprotruding end of therivet. .ment imparted to the rivet assembly will first Another objectof. myinvention is to provide a draw the workpieces into tightengagement with tubular rivet of thecharacterdescribed wherein eachother and then the protruding end of the the rotary movement impartedtothe rivet astubular' rivet will be upset to secure the rivet sembiy isimparted through the mandrel, the fi y in p e in t e wo kpieces. 10mandrel being threaded into the rivet body with In the art of rivetingtwo or more workpieces threads, the pitch of which is opposed to theextogether such as two-or more sheets of metal 'ternal threads on theshank, whereby rotating or. similar material which are required to bethemandrel will first rotate the entire'assembly secured together, it isthe common practice to bore until the worksheets have been drawn tightly.holes through the superimposed work sheets and together. and thencontinued rotary movement extend therefihrough a rivet Which When upsetwill imparted to. the mandrel will cause the mandrel firmly hold theworkpieces together. In many to be drawn inwardly of the rivet body toupset the situations the locations-of the workpieces are such protrudingend of the rivetbody shank. that it is impossible to obtain access tothe rear Another object of my invention. isto provide a sideof theworkpieces andin such cases a blind rivet of the. character describedwherein the rivet rivet must be used comprising a rivet body hav-.mandrelmaybemanipulated to perform first .ing a shank sufficiently longto project through the functions of tightening. thevrorkpieces .or .,thesuperimposed workpieces and to extend bework sheets-upon each other andthen to upset the ,yond the inner side of the inner workpieca theprotruding. endoiv the. rivet body shank without rivet assemblyincluding a mandrel extending requiring anysuch tools. asare requiredfor. imthrough the rivet body and adapted to be actupartingan. axialpull between v.rive t. bodies .and ated from thefront side of'theworkpieces or work their mandrels in. the ordinary blind. rivetconsheets to upset the protruding end of the rivet to .structiom a..thereby secure therivet in place. I I Qther obiectsand advantages ofmy invention Frequently it occurs that the superimposed will beapparentfrom a studyof the following workpieces do not have] theirfaces'in intimate specifications. readin connection withtheaccomcontact. with each other prior to the riveting oppanv'ingdrawing, wherein: oration and it is. therefore, de b e t at e .liig.lisavertical sectional view taken through operation of upsetting therivet shouldffirst draw a rivet assemblyconstructedin accordance withthe work sheets or workpiece o. t e des ed 5 .my invention-andillustrating the position of the relation with each other and. then theprotruding partswhen initially inserted together in aligned E Of therivet y Shank Sh be p e to rivet holes in a pair of workpieces or worksheets; secure the rivet in place. V .1 Fig.2 is a vie-w. similar toFig. land illustrating It is, therefore. an object of my invention. tothe position of. the parts at the endof the upsetprovide a tubular rivetof the blind rivet type ting gperati0141s; and,v r p I l Which y he so mn pu d as tofir tc u e the 1 Figi3is a view similarto Figs, 1 ands andillusp c 30 e d n ti h y against 1 1. 6 trating the position. offt eparts at the .end of pr t h up t i f he pro ruding end f the upsetting.operations and after the stem .of the rivet. g .the mandrel has beenbroken off. Another object of my invent'ion is to provide a LReferringto thedrawingl have illustrated a pairof. workpiecesAandB as a ,pair ofsheets of material .to. befsecured togethenv by means of a headportionifi and a, tubular shank the length of which issuificient to passthrough rivet assemblyjcomprisinga rivet body I and a mandrel 2.extending longitudinally. therethrough. Theri-vtbOdy. I. isprovided.with anenlarged portion 4,

both of the .work sheets and to protrudea suf- .ficient distanceinwardly.of. ..the inner work sheet .B' to permit of the upsetting oithe protruding end having the portion immediately adjacent the headformed with a smooth cylindrical exterior surface adapted to be receivedin a smooth cylindrical bore or rivet hole C formed'in the outer worksheet A, the remaining portions of the shank of the rivet body beingthreaded as indicated at 5 for threaded reception in a threaded bore orrivet hole D formed in the inner work sheet'B.

The mandrel 2 is disposed to extend through a longitudinal bore 6extending throughout the length of the rivet body head and shank, aportion of the bore adjacent the head'3 being threaded as indicated at Ito receive a threaded portion 8 of the mandrel 2. p

By referring particularly to Fig. 1, it will be observed that themandrel has an enlarged upsetting head 9 formed on its extreme inner endwhile between the head 9 and the threaded portion 8 there is a smoothcylindrical portion Iii adapted to be received tion of the bore 6. Themandrel 2 is provided with a protruding stem portion II preferablyflattened as indicated at I2 at its extreme outer end to permit theengagement therewith of any suitable tool such as a wrench, pair ofpliers or the like for imparting a rotary motion to the assembly.

It should be noted from an inspection of Fig. 1 that the externalthreads on the rivet s ank have a pitch in one direction, for example,righthand. while the threads I on the interior of the shank have a pitchin the opposite direction, for example, left-hand. so that when therivet assembly is to be inserted into the aligned holes C and D in apair of workp eces a right-hand rotary motion imparted to the mandrelstem I I wi l first cause the shank of the rivet body to be screwed intot e threaded hole D in the inner work iece until the under surface ofthe rivet body head is drawn into engaging relation with the outersurface of the outer work iece A and any further rotary movementimparted to the rivet body will result in drawing the two workpiecesinto tight relation one upon the other. During this initial rotarymovement. the fact that the threads between the mandrel and the rivetbody bore are in an opposite d rection to the threads exteriorly of therivet body shank, there will be no relative ro ary movement between themandrel and the body.

When the rotary motion of the rivet body is stooped as the plates orworkpieces are drawn into tight relation with each other, a further 4right-hand rotary motion im arted to the mandrel stem will cause themandrel to be screwed into the rivet body in such direction as will drawthe upsetting head 9 of the mandrel into the bore 6 of the body, trudingend I3 of the rivet body shank will be radially ex anded as indicated inFig. 2 to securely fix the rivet assembly in place. 7

When the mandrel has been drawn inwardly of the rivet body shank to comletely unset the protruding end of the shank, the resistance to furtherinward movement of the mandrel will be such as to cause the mandrel stemI I to break when further rotary force is exerted on the mandrel. I4about the stem II at such posi ion spaced from the u setting head 9 asto cause the mandrel to break at a point which will be approximatelyflush with the outer surface of the head 3 of the rivet body, suchcondition being illustrated in in a smooth surfaced por-' with theresult that the proand I prefer to provide an annular groove Fig. 3,wherein the protruding end I3 of the rivet body shank has been expandedor upset to secure the rivet assembly in place and the mandrel has beenbroken off at the groove I4 approximately flush with the outer surfaceof the head of the rivet body.

From theforegoing tubular rivet constructed in accordance with myinvention provides not only for the upsetting of the shank of the rivetbody but also provides for an initial exertion of forces tending to drawthe workpieces together and a subsequent expansion of the shank of therivet body to secure the rivet in place. By employing the rotarymovement as distinguished from an axial pull exerted between the rivetbody and mandrel and utilizing the threaded interengagement of themandrel with the rivet body, backlash or tendency for the mandrel tomove outwardly in the rivet body at the instant of fracture of the stemis avoided and a tight engagement between the rivet body and mandrel atthe end of the upsetting operations is assured.

It will be apparent also from the foregoing that with a rivet assemblyas illustrated and described herein, the rivets may be readily set by aworkman using any conventional tool adapted to grip the extending stemof the mandrel to impart a rotary motion thereto, such as wrenches,pliers and the like, which are readily available to the workman, and theassembly requires no special tool for its insertion and manipulation.

While I have shown and described the preferred embodiment of myinvention, I do not desire to be limited to any of the details ofconstruction shown and described herein, except as defined in theappended claims.

I claim:

1. In a tubular rivet assembly for securing a pair of workpiecestogether, a rivet body having a head and a shank extending therefrom forreception in aligned holes in an outer and inner workpiece to be securedtogether, said shank having a length sufiicient to permit it to passthrough the workpieces and protrude beyond the inner surface of theinner workpiece, threads on the exterior of said shank to threadedlyengage'at least the inner workpiece, a longitudinal bore extendingthrough said shank and having threads threaded to a pitch opposed to theexternal threads on said shank, a mandrel disposed in said bore andthreadedly engaging the threads in said bore, said mandrel having anenlarged head at one of its ends disposed adjacent the end of the shank,and a stem extending beyond the head of the rivet body whereby rotarymovement imparted to the stem of said mandrel will first thread theshank into the workpieces and further rotary movement imparted to saidstem will cause said mandrel to be moved inwardly of said rivet body toexpand the end of said shank into riveted relation with said workpieces.

2. In a rivet assembly, the combination of a rivet body having a headand a shank extending therefrom adapted to extend through aligned holesin outer and inner workpieces to be riveted together, said shank havingthat portion of its length which is to be disposed within the hole inthe inner workpiece threaded and the remainder of said shank beingunthreaded for reception in a smooth surfaced hole in the outer worksheet, a longitudinal bore extending through said rivet body, head andshank, and a mandrel disposed in said bore and having threadedengagement with said bore, said mandrel including an enit will beapparent that a i 5 7 iarged upsetting head disposed adjacent the innerwill firstcause said shank to be threaded into end of the shank and astem portion extending an inner workpiece until the workpieces areoutwardly of the head of the rivet body, the clamped in tight relationto each other and furpitch of the threads on the exteriorof the shankther rotary movement imparted to said stem will and the threads on themandrel and bore being 5 cause said mandrel head to be drawn inwardlyopposed to each other whereby rotary movement of the shank to upset theend of the shank. imparted to the stem portion of said mandrel HERBERTJ. KEATING.

